Generally, trailer tires don’t wear evenly: When a tandem axle trailer with four tires takes a tight turn, the inside tires will “slide” a bit rather than roll, because they have significantly less distance to travel.
That said, rapid or significantly uneven trailer tire wear can be caused by:
- Running with the wrong tire pressure.
- Exceeding your trailers’ load capacity.
- Trailer misalignment or bent wheels from hitting curbs, potholes or debris.
- Not towing level, which puts more weight and strain on one axle.
- Uneven load management instead of spreading weight evenly to all wheels/tires.
If all four tires are wearing heavily on the inside, the trailer is probably overloaded.
When the load is too heavy, the axle bows downward in the middle, causing the tires to roll pigeon-toed (more on the inside shoulder of the tires). That’s not the normal contact patch for tires, and you’ll see pronounced wear there.
If only one tire is wearing faster on the inside, you may have a bent suspension part, like a spindle or torsion arm. This can cause one tire to skid rather than roll smoothly down the road, creating heat and friction that wears out the rubber.
If you notice tire cupping — a bulge on one area of the tire — the belts or plies inside (the strong cords of steel and nylon that give the tire its strength) are failing. It can be caused by wheel bearing problems, bad alignment or something worn out in your suspension. It can also result from excessive heat caused by going over the speed rating of your tires.
Tires on a trailer parked for a long time can develop flattened spots in the area that contacts the ground. To prevent this, simply move your trailer regularly.